lib: only trigger phrase processing for regexp fields when needed

The argument is that if the string passed to the field processor has
no spaces, then the added quotes won't have any benefit except for
disabling wildcards. But disabling wildcards doesn't seem very useful
in the normal Xapian query parser, since they're stripped before
generating terms anyway. It does mean that the query 'from:"foo*"' will
not be precisely equivalent to 'from:foo' as it is for the non
field-processor version.

lib/regexp-fields.cc

@@ -158,8 +158,14 @@ RegexpFieldProcessor::operator() (const std::string & str)
     } else {
 	/* TODO replace this with a nicer API level triggering of
 	 * phrase parsing, when possible */
-	std::string quoted='"' + str + '"';
+	std::string query_str;
-	return parser.parse_query (quoted, NOTMUCH_QUERY_PARSER_FLAGS, term_prefix);
+
+	if (str.find (' ') != std::string::npos)
+	    query_str = '"' + str + '"';
+	else
+	    query_str = str;
+
+	return parser.parse_query (query_str, NOTMUCH_QUERY_PARSER_FLAGS, term_prefix);
     }
 }
 #endif

test/T650-regexp-query.sh

@@ -12,12 +12,10 @@ fi
 notmuch search --output=messages from:cworth > cworth.msg-ids
 
 test_begin_subtest "xapian wildcard search for from:"
-test_subtest_known_broken
 notmuch search --output=messages 'from:cwo*' > OUTPUT
 test_expect_equal_file cworth.msg-ids OUTPUT
 
 test_begin_subtest "xapian wildcard search for subject:"
-test_subtest_known_broken
 test_expect_equal $(notmuch count 'subject:count*') 1
 
 test_begin_subtest "regexp from search, case sensitive"